Lipid metabolism study in Women Pregnancy induced Hypertension Cases

Abstract

This cross sectional study was conducted on the pregnant women attending the Gynecology and Obstetrics Department of tertiary care hospitals of Peshawar, North West Frontier Province (NWFP) Pakistan. A total of 402 pregnant women at gestational age of > 20 weeks were registered in the study after taking their informed consent. The study subjects were divided into four groups of pregnant women; with three patient groups (A, B, C) of Pregnancy Induced Hypertension (PIH) and one control group (D).
History of each participant was recorded on a pre designed questionnaire. Height, weight and blood pressure was measured and 5 ml of venous blood was drawn from patients and control groups. Biochemical analysis of lipoprotein included Total Cholesterol (TC), High Density Lipoprotein Cholesterol (HDL-C), Low Density Lipoprotein Cholesterol (LDL-C), Very Low Density Lipoprotein Cholesterol (VLDL-C), Triglycerides (TG), Apolipoprotein-A1 (APO-A1), Apolipoprotein- B100 (100), Lipoprotein-a (LPA) and hematological parameters including Hemoglobin (Hb) and Platelet count. These investigations were performed in PMRC Research Centre, Khyber Medical College, Peshawar and in the Pathology labs of Post Graduate Medical Institute (PGMI) Lady Reading Hospital, Peshawar. The data was processed on computer software package SPSS version 10.
Statistically highly significant (P < 0.001) differences were noted in most of maternal serum lipids and lipoprotein concentrations in the three individual patient groups when compared with the control pregnant women, except changes in LDLC (P > 0.05). Changes in the TC were non significant in group A and B, while difference in group C were significant (P < 0.05) when compared with the control group D. Similarly was non significant (P > 0.05), markedly significant (P < 0.01) and highly significant (P <0.001) in group A, B & C respectively when compared with group D. Mean concentrations of 100 were non significant in group B, while it was significant (P < 0.05) in group A and C when compared with group D. Changes in the mean values of LPA were non significant in group A and B, while it was highly significant (P < 0.001) in group C as compared to control group D. Amongst the different lipoprotein ratio TC: HDL-C, LDL-C: HDL-C, TG: HDL-C and HDL-C: VLDL-C ratio were found highly significant (P < 0.001) in patient groups of A, B and C, as compared with group D. Women who developed hypertension (group A+B+C) had 5.45%, 3.5%, 39%, 38.6% and 26.98% higher concentrations of TC, LDL-C, VLDL-C, TG and LPA levels respectively, than control subjects. A significant decrease of (16.76%) and (18.5%) was respectively noted in HDL-C and APO-A1 of patient group when compared with control pregnant women, while no significant change in 100 levels was seen among the groups. TC: HDL ratios, LDL-C: HDL-C ratio and TG: HDL-C ratios were higher (32.3%, 29.8% & 66.4% respectively) among women with PIH and were found highly significant (P<0.001) as compared to normotensive women. In the PIH group LDL-C: 100 was raised to the marked significant level of P < 0.01, while the difference between the two groups of test and control was found non significant for LDL-C: 100 ratio (P > 0.05). HDL-C: VLDL-C ratio were decreased by 38.23% in the patients and were highly significant as compared with control subjects (P <0.001).
A significant difference was found in maternal TG levels, VLDL-C, TC: HDL-C, TG: HDL-C and HDL-C: VLDL-C ratio, when the PIH group of patients with systolic blood pressure (SBP) < and > 150 mmHg were compared. Similarly PIH patients had significantly elevated serum HDL-C, VLDL-C, TG, TC: HDL-C, TG: HDL-C, HDL-C: VLDL-C and LDL-C: 100 ratio when patients with diastolic blood pressure (DBP) < 110 were compared with DBP > 110 mmHg. Undesirable TC > 240 mg/dl in 35.8% patients, undesirable HDL-C in 50% patients, high concentrations of TG (73.2%), borderline high concentration of LDL-C (23.6%), undesirable TC ratio > 5.2 in 52.3% and undesirable LDL-C ratio > 1.6 were noted all in the patients of eclampsia group ‘C’.
A 1.5-fold increase in the risk of PIH among women with TC >240 mg/dl was noted, as compared with women whose TC concentration was < 200 mg/dl (95% CI (0.80-2.75) χ2 1.81, P 0.17). Women in the lowest group of HDL-C concentration, experienced an 8.6-fold increased risk of PIH as compared with women in the highest group (95% CI (3.28-22.71) χ2 27.9, P <0.0001) as referent. The women having LDL-C in the range of 130-159 mg/dl experienced a 1.5-fold increased risk of PIH as compared with women in the lowest group (95% CI (0.67-3.40). Women in the TG concentrations (200-499 mg/dl) experienced a 3.5- fold increased risk of PIH as compared with those women in the lowest group as referent (95% CI (1.50 to 8.22) χ2 10.82, P < 0.001). The risk of PIH increased 4.5 times for HDL-C ratio > 5.1 (95% CI (2.-8.87) χ2 24.39, P < 0.0001). Women with the highest LDL-C: HDL-C ratio experienced an almost 2.4-fold increased risk of PIH (OR 2.43, 95% CI 1.18 to 4.98, χ2 7.09, P 0.007) as compared with women whose ratio values were <1.21 (lower group).
A significant change was seen in the concentration of HDL-C (P < 0.01), VLDLC (P < 0.05), triglycerides (P < 0.05), 100 (P < 0.05) and LPA (P < 0.05), when PIH women in the second trimester were compared with those in their third trimester. Significant changes were observed in the systolic (P< 0.05) and DBP (P < 0.01) of PIH women, when 2nd trimester was compared with the 3rd trimester.
In the patient group 85.6% pregnant women were anemic as compared to 84.5% in the control group. Majority of women with severe anemia (Hb < 7.7 g %) were present in the three patient groups as compared to the normal pregnant women. Normal platelet count > 150 thousand/µL was recorded in 85 (95.5%) of control pregnant women against 70 (78.3%) in the group of PIH. The number of women with severe thrombocytopenia (platelet count < 100 thousand/µL) were more in group C of eclampsia (13.6%) versus 1.1% in the control women.
In conclusion, the results of our study propose that an abnormal lipid metabolism and predominantly low HDL-C and high TG concentrations, may add to the promotion of vascular dysfunction and oxidative stress seen in pregnancy induced hypertension. It is, therefore, essential that, blood lipid concentrations be estimated in pregnant women during antenatal care since it could be useful in the early revealing and prevention of obstetric complications such as pregnancy induced hypertension.